While Bruce and Kris Jenner announced their separation almost a year ago and both filed for divorce just last month, officially ending their 22-year marriage, Kris, 58, admitted the thought of dating again was "daunting" to her.
However, a source reveals to PEOPLE exclusively that Bruce, 64, has already begun a new romance – and it's with Kris's longtime friend and former assistant, Ronda Kamihira.
"Kris is devastated," says the source. "This was her former assistant and best friend of 20 years."
The source adds that the Jenners' daughters, "Kendall and Kylie grew up with her two kids and have been their best friends."
After such an amicable split with the former Olympian, Kris "is just shocked" by the news. "She's so sad and completely heartbroken," the source adds.
Just months earlier, Kamihira joined her girlfriend Kris for a getaway to Kardashian family friend Joe Francis's Punta Mita compound.
Bruce, Kris and Kamihira were not immediately able to be reached for comment.